Viral Marketing, simply put, is the cause and effect your offerings have on the impressionable mindsets of immediate users. This phenomenon hits the size of a global audience of billions in no time at all if done right.
Thus, when something goes on to reach this gigantic scale of exposure, it is termed a viral trend, especially when a majority of the people in question think it to be worthy enough for sharing & propagating to their connections.
There are uncountable confirmed stories of people going from rags to riches almost overnight as a result of the accompanying fame & fortune; as the resulting reach brings with it more followers, which equates to more product placement opportunities.
These case studies are not plain and simple flukes, but are in actuality the results of carefully researched and well-planned campaigns by industry veterans, who more often than not play along given lines of uniqueness (a given situation or a set of given circumstances).
This is the human psyche at it’s finest. Brands are introduced later on in the scheme of things and sustained as a course of action.
This, by far, is the most optimal use of the internet, with an audience of billions within the span of a single day!